Association of serum Vitamin D 、C-reactive protein with multiple causes of death outcomes in obese adult population: The United States National Health and Nutrition Examination Survey, 2001 to 2006

Abstract

Background Levels of chronic inflammation are common in individuals with obesity, and recent studies have indicated a high prevalence of vitamin D deficiency among this population. However, studies on the relationship between vitamin D levels and C reactive protein (CRP) levels which is the markers of inflammation in the body and the risk of death remain unclear. Purpose This study focuses on the association between serum vitamin D (25(OH)D), CRP, and mortality risk and whether there is an association for mortality risk in different dietary inflammatory structures in obese adults. Methods This study included 4,469 adults with obesity from the National Health and Nutrition Examination Survey (NHANES). A multivariate adjusted weighted Cox model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for multiple causes of death outcomes. Results 25(OH)D level is significantly negatively associated with the risk of all-cause mortality. According to results of the joint action analysis, it was found that HCLD group had the highest risk of all-cause mortality compared to the LCHD group. There was a significant interaction between vitamin D and CRP in the risk of all-cause mortality (p=0.006). Furthermore, the interaction between two makers were particularly evident in the pro-inflammatory dietary pattern. Conclusions 25(OH)D level is closely related to the risk of all-cause mortality. In particular, the risk of all cause death is highest among individuals with high CRP and low serum levels of vitamin D. Moreover, there is a significant interaction between 25(OH)D and CRP, especially in pro-inflammatory diets.